Q4.2.a
Approximately what is the radius of
a copper atom?
1) 1 e -15 m
2) 1 e -12 m
3) 1 e -10 m
4) 1 e-8 m
5) 1 e-6 m
Q4.4.a
How does the diameter of one atom
in a solid compare to the length of
an interatomic bond?
1) The bond length is
greater than the atomic
diameter
2) The bond length is less
than the atomic diameter
3) They are the same
Q4.4.b
The mass of one atom is m (kg/atom).
The density of solid copper is  (rho)
(kg/m3).
1) m*
2) m/
3) /m
What is the volume occupied by one atom 4) m*(3)
of copper in a solid?
Q4.5.a: Springs in “series”
You hang a 1 kg mass from a
spring, which stretches 0.4 m.
How much does this longer
spring stretch?
You link the spring end to end with
another identical spring, and hang
a 1 kg mass from the linked
springs.
1) 0.16 m
2) 0.2 m
3) 0.4 m
4) 0.8 m
Q4.5.b: Springs in “series”
A short spring has a stiffness
of 20 N/m. You link 4 of these
springs end to end to make a
longer spring.
What is the stiffness of the
longer spring?
1) 0.2 N/m
2) 5 N/m
3) 20 N/m
4) 80 N/m
Q4.5.c: Springs in “parallel”
You hang a 1 kg mass from a
spring, which stretches 0.4 m.
How much does
each spring stretch?
You place a second identical
spring beside the first, so the
1 kg mass is now supported
by two springs.
1) 0.2 m
2) 0.4 m
3) 0.5 m
4) 0.8 m
Q4.5.d: Springs in “parallel”
A short spring has a stiffness of 20 N/m.
You use 4 of these springs side by side
to support a mass.
What is the stiffness of the 4 side-byside springs, considered as one
effective spring?
1) 0.2 N/m
2) 5 N/m
3) 20 N/m
4) 80 N/m
Q4.6.a
Lead is much softer than
aluminum, and can be more
easily deformed or pulled into
a wire.
What difference between the
two materials best explains
this?
1) Pb and Al atoms have
different sizes
2) Pb and Al atoms have
different masses
3) The stiffness of the
interatomic bonds is different in
Pb and Al
Q4.6.b:
You hang a 10 kg mass from a
copper wire, and the wire
stretches by 8 mm.
Now you hang the same mass
from two copper wires,
identical to the first.
What happens?
1) Each wire stretches 4 mm
2) Each wire stretches 8 mm
3) Each wire stretches 16 mm
Q4.6.c:
You hang a 10 kg mass from
a copper wire, and the wire
stretches by 8 mm.
What happens?
1) The second wire stretches
4 mm
Now you hang the same mass 2) The second wire stretches
from a second copper wire,
8 mm
whose cross-sectional area is 3) The second wire stretches
half as large (but whose
16 mm
length is the same).
Q4.6.d:
You hang a 10 kg mass from
a copper wire, and the wire
stretches by 8 mm.
What happens?
1) The second wire stretches
4 mm
Now you hang the same mass 2) The second wire stretches
from a second copper wire,
8 mm
which is twice as long, but
3) The second wire stretches
has the same diameter.
16 mm
Q4.6.e
Two wires with equal lengths are
made of pure copper. The
diameter of wire A is twice the
diameter of wire B.
When 6 kg masses are hung on
the wires, wire B stretches more
than wire A.
Y = (F/A)/(L/L)
You make careful
measurements and compute
Young's modulus for both
wires. What do you find?
1) YA > YB
2) YA = YB
3) YA < YB
Q4.8.a
You push a 100 kg mass
on the floor with a
horizontal force of 400 N. It
doesn’t move.
The coefficient of static
friction is 0.6.
What is the magnitude
of the frictional force
on the block by the
floor?
1) 980 N
2) 588 N
3) 400 N
4) Can’t tell
Q4.8.b
You push an initially
stationary 100 kg mass on
the floor with a horizontal
force. The coefficient of
static friction is 0.6.
What is the minimum
amount of force you
need to exert on the
mass in order to get it
to move?
1) 980 N
2) 588 N
3) 400 N
4) Can’t tell
Q4.8.c
You push a 100 kg mass on
the floor with a horizontal
force of 400 N, and it’s
moving in the direction you
are pushing. The coefficient
of static friction is 0.3.
What happens to the
speed of the block while
you push it?
1) The speed increases
2) The speed decreases
3) The speed does not change
4) Can’t tell
Q4.8.d
You push a 100 kg mass on
the floor with a horizontal
force, and it’s moving in
the direction you are pushing
at a constant speed. The
coefficient of static friction is
0.3.
How much force are you
exerting on the block?
1) 980 N
2) 294 N
3) 490 N
4) Can’t tell
Q4.11.a
Suppose the period of a
spring-mass oscillator is 1 s.
What will be the period if we
double the mass?
1) T = 0.5 s
2) T = 0.7 s
3) T = 1.0 s
4) T = 1.4 s
5) T = 2.0 s
Q4.11.b
Suppose the period of a
spring-mass oscillator is 1 s.
What will be the period if we
double the spring stiffness?
(We could use a stiffer spring,
or we could attach the mass to
two springs.)
1) T = 0.5 s
2) T = 0.7 s
3) T = 1.0 s
4) T = 1.4 s
5) T = 2.0 s
Q4.11.c
Suppose the period of a springmass oscillator is 1 s with an
amplitude of 5 cm. What will be the
period if we increase the amplitude
to 10 cm, so that the total distance
traveled in one period is twice as
large?
1) T = 0.5 s
2) T = 0.7 s
3) T = 1.0 s
4) T = 1.4 s
5) T = 2.0 s
Q4.11.d
Suppose the period of a
spring-mass oscillator is 1 s.
What will be the period if we
cut the spring in half and use
just one of the pieces?
1) T = 0.5 s
2) T = 0.7 s
3) T = 1.0 s
4) T = 1.4 s
5) T = 2.0 s
Q4.11.e
In a spring-mass oscillator,
when is the magnitude of
momentum of the mass
largest?
1) When the magnitude of the
net force acting on the mass is
largest.
2) When the magnitude of the
net force acting on the mass is
smallest.
Q4.11.f
Suppose the period of a
spring-mass oscillator is 1 s
with an amplitude of 5 cm.
What will be the period if we
take the oscillator to a
massive planet where g = 19.6
N/kg?
1) T = 0.5 s
2) T = 0.7 s
3) T = 1.0 s
4) T = 1.4 s
5) T = 2.0 s
Q4.12.a:
The atomic mass of aluminum is 27. In calculating the speed of sound in
aluminum using the formula v  d k s / m , m is
1) 27 grams
2) 27 kilograms
3) Something else